If you thought that living in with your mom in your 20s or being in a trailer was weird: HE lives in a PINEAPPLE!
This sea sponge is the physical embodiment of optimism and naivete, as he always wants to be a source of positivity for the people he cares deeply for. Whether it be his best friend Patrick Star, his abrasive and annoyed neighbor Squidward, his boss and owner of the Krusty Krab Mr Krabs, or his Texan friend Sandy, despite him not being the strongest, or the most bold, he's known well around Bikini Bottom - for better, or for... not better. His hobbies mainly include bubble-blowing and jellyfishing.
He lives under a rock, he does nothing all day, and he thinks that mayonnaise is an instrument. What a great friend!
Patrick being SpongeBob's friend is a bit of an oddity, as they are in a way polar opposites. While SpongeBob is pretty composed, smart and down-to-earth most of the time (less Patrick's influence gets in the way), he on the other hand... is dim-witted and a lazy slob who can get angered or jealous very easily. Despite this, he still tries to overcome his negative traits and be in the moment when it's most needed. His favorite hobbies are doing nothing all day.